O.K. (????ke?) sentence substitutean expression of approval, agreement, etcadj, adv (usually postpositive) 1. in good or satisfactory condition2. permissible: is it O.K. if I go home now?. 3. acceptable but not outstanding: the party was O.K.. vb, O.K.s, O.K.ing (????ke???) or O.K.ed (????ke?d) (tr) to approve or endorsen, pl O.K.sapproval or agreement Also: OK, o.k. or okay [C19: perhaps from o(ll) k(orrect), jocular alteration of all correct]Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014O.K. See AFFIRMATION.rubber stamp To approve as a matter of course; to authorize without the proper examination or review. This phrase is derived from the rubber stamps used in lieu of a signature on documents, bank checks, etc. The expression is often applied adjectivally to describe persons or groups without a will or mind of their own, whose decisions and judgments are totally determined by others.He has been more of a rubber stamp voter than most so-called ?machine? officeholders. (Chicago Sun Times, April, 1948)thumbs up Approval, approbation, affirmation. This expression stems from the days when gladiators fought in the Roman Colosseum and other large amphitheaters for the entertainment of the spectators. When one of the combatants was clearly vanquished, the victor would look to the crowd before making his next move?thumbs up (thumb close to or inside a closed fist) indicated that the throng approved of the effort expended by the loser, and his life was spared. Thumbs down (thumb extended downward from a closed fist) signified disapproval, and gave the winner the license to slay his opponent. Eventually, thumbs up was demonstrated by making a fist, extending the thumb, and pointing it upward. This gesture assumed a cultish popularity in the 1950s as evidenced by its frequent use in the ABC television series Happy Days, a situation comedy that started in 1974. See also thumbs down, REFUSAL.